Cylindrical scanning



July 21, 1931. w. HOwEY 1,815,105

GYLINDRICAL SCANNING Filed June 20, 1930 Inventor Attorney atented July 21, 1931 UNITED STATES WALTER HOWEY, OF NEW YORK, N. Y.

O'YLINDRICAL SCANNING Application filed June 20,

My invention relates to cylindrical scanning and it more especially consists of the features pointed out in the annexed claims.

The purpose of my invention is'to-simul- 6 taneously use the same cylindrical device for scanning and engraving any desired subject; that produces rotary motion of a connected cylindrical surface and simultaneously produces coordinate movement of the scan- 10 ning and engraving means adjacent the latter; that ma use any desired form of scanning by re ected light, transmitted light, mechanicalmeans or otherwise; that may utilize any desired form of engraving apparatus; and that may have more than one cylinder and its engraving device mechanically connected to the scanner.

With these and other ends in view I illustrate in the accompanying drawings such instances of adaptation as will disclose the broad underlying features of my invention without limiting myself to the specific details shown thereon and described herein.

Figure 1 is a dia rammatic top plan view.

Fig. 2.is a detac ed enlargement in cross section of a carriage and its riding bars and lead screw.

Fig. 3 is a diagrammatic cross section of a motor drive.

In practicing my invention I may use whatever alternatives or equivalents of structure that the exigencies of varying demands may make without departing from the broad spirit of the invention.

It has been proposed heretofore to scan and record in an engraved manner on fiat surfaces to which reciprocating movement is imparted, as instanced in Patent No. 1,719,621 issued July 2, 1929 to Pearne et al. These expedients involve the to and fro motion of the flat beds on which the subject and the engraving material are placed. In addition to the to and fro movement a periodic transverse shift of the tables must take place at the end of each lineal traverse. The intermittent stopping and starting of the various motions are a relatively slow procedure. Cylindrical scanning and engraving at the same time on the same device permits of greatly increased speeds. The shock and jar of re- 1980. Serial No. 462,667.

versing moving parts, inevitably associated with fiat bed devices, are entirely eliminated.

My device is a unitary mechanism. It comprises a scanning cylinder 3, and engraving or reproducing means 4, 18, on a single bed or frame 1. The two cylinders 3 and 4, as instanced in the drawings are mounted on the shaft 5 which may be driven by a motor 2 through a worm gear 6, positioned on the shaftv5, between the cylinders. This relation of motor drive is immaterial as alternatively it may be at one end of the shaft 5, and instead of using two separate cylinders only a single one may be adopted, excepting when the scanning is done by transmitted light. The subject and engraving material may be secured to the cylinders by means of elastic bands etc., or by mechanism such as is used in securing the blankets on the tympan cylinder 0f rotary printing presses but as these expedients are well known and form no part of the present invention they are not shown.

The frame 1 comprises a conventional base. and two ends 23 which stand upright. In these the outer bearings for the shaft 5 are placed, and also the bearings for the feed screw 7. Intermediate bearings 24 may be used for the shaft 5, on each side of the worm gear 6. The feed screw 7 is enclosed in a tubular riding bar 8. At the ieft hand end of the frame it has a change gear 17 that meshes with another change gear 17 on the adjacent end of the shaft 5. The feed screw 7 is only threaded for a fpart of its length. It is engaged by a hal nut 10 attached to a finger 8 lever 11 which is pivoted at 12 to the rear of the scanner carriage 14. The nut 10 is kept in engagement with the threads of the feed screw 7 by means of a spring 13. It operates through a slot 9 formed in the under side of the hollow riding bar 8. The slot may extend for only a part of the length of the riding bar. As instanced in the drawings the scanner is at the extreme left end of its traverse.

To prevent the carriage 14 jamming the end frame 23, the threads of the feed screw 7 are omitted by reducing its diameter for a little more than the width of the half nut 10. If the scanning is to be at the left hand @nd of 100 the cylinder 3, the engraving carriage 19 is prevented jamming against the right hand end 23 of the frame 1 by reason 0 threads being omitted near the mid-length of the screw, as shown in dotted lines on Fig. 1.

The scanning carriage 14 and the reproducing carriage 19 are rigidly connected to each other by means of a connecting bar 15, which slides on an intermediate riding bar 16. If desired, these carriages may be held together separably by means of any well known form of locking device. They may be turned back ward on the riding bar 8 by releasing the half nut 10 from the feed screw so that it will engage the outside of the riding bar. A suitable stop 25 may be placed on the carriage 19 so as to abut the intermediate riding bar 16 when the carriages are swung backward, and thus limit the extent of their rearward movement.

In the instanced illustration in the drawings, a light sensitive scanner 21 is positioned on the carriage 14. It is electrically connected to the recorder or graver 18, which connection may be an amplifying circuit 20. To assist in observing the subject or the reproduction, an observing microscope 22 may be mounted in any desired manner on the carriages 14 and 19. Its position on the carriage 14 is suggested in Fig. 2. It may be associated with any cooperating means, such as a prism, etc.

This invention generally relates to the use of any kind of engraving means but it is speciall applicable to any means for directly pro ucing engravings from a scanned subject, such engraving being either in intaglio or the reverse for relief printing.

It will be readily understood that by means of well known mechanical expedients (not shown) the engraving produced on the cylinder 4 may be reversed from left to right by using a right hand feed screw 7 for the scanner and a left hand feed screw 8 for the engraver, in which event the scanner may start at the left hand end of the cylinder 3 and the engraver may start at the hight hand end of the cylinder 4, the scanner and engraver moving towards each other. Or separate intergeared feed screws may be used to secure the same result. Engravings as used for printing purposes must be reversed as to right and left so that when finally printed on paper the reproduction will be in normal position.

What I claim is:

1. In devices for photoelectrically engraving plates for printing, in combination, a rotatable cylinder adapted to support a picture, a light sensitive scanning means, adjacent said cylinder, means for producing a. transverse movement of the light sensitive scanning means relative to the picture, a resistance coupled amplifying system suitably connected to the output of the light sensitive scanning means, a suitable engraving device, adapted to engrave in a suitable plate a. facsimile of the picture suitable for direct printing, connected to the Output of the amplifying means, a second rotatable cylinder adapted to hold a plate to be engraved, means for moving the engraving device synchronously with the light sensitive scanning device and transversely relative to the cylinder holding the plate to be engraved, means for coupling the two cylinders each to the other and means for producing synchronous rotation of the cylinders.

2. In devices for photoelectrically engraving plates for printing, in combination, a rotatable cylinder adapted to hold a picture at one end and a plate to be engraved at the other end, a light sensitive scanner adjacent the end of the cylinder adapted to hold the picture and a suitable engraving device responsive to the amplified output of the light sensitive scanner adjacent the end of the cylinder adapted to hold the plate to be engraved, means for moving the light sensitive scanner and the engraving device synchronously in transverse relation to the cylinder, and means for amplifying the output of the light sensitive scanner to cause the engraving device to engrave in a suitable plate a facsimile of the picture, suitable for direct printing.

In testimony whereof I affix my signature.

WALTER HOWEY. 

